In this study, the co-precipitation method was adopted to synthesize red phosphor CaO: Eu3+. Sodium carbonate was chosen as the precipitator, and sodium dodecylbenzensulfonate as the surfactant. The structure, morphology, and spectroscopic properties of the samples were characterized by XRD, laser particle size analyzer, SEM, FT-IR, Raman, UV-Vis and PL-PLE spectra, respectively. The results indicated that the Eu3+ ion inhabited the site of Ca2+ as the luminescent center, and the crystal structure of cubic CaO remained unchanged. The particle size of the obtained product was 0.5-2 mu m with smooth surface. There was a main intense band with a maximum at 250 nm, which was attributed to the charge transfer transition of Eu3+-O2- and the maximum emission wavelength is 592 nm, corresponding to magnetic dipole transitions D-5(0) -> F-7(1) of Eu3+ in the excitation spectrum.